pinctrl: single: AM437x: Add pinctrl compatibility

AM437x pinctrl definitions now differ from traditional 16 bit OMAP pin
ctrl definitions, in that all 32 bits are used to describe a single pin

Also the location of wakeupenable and event bits have changed.

Signed-off-by: Keerthy <j-keerthy@ti.com>
[nm@ti.com: minor updates]
Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>